The Sun, the Earth and the Weather is the theme of this year’s World Meteorological Day. It highlights the role of the Sun in delivering the energy that powers all life on Earth, and drives the weather, ocean currents and the hydrological cycle.

Scientists have been observing changes in the climate that cannot be attributed solely to natural influences. These changes are occurring rapidly, are significant, and will have consequences for this and future generations. Changes in climate variability and extremes driven by human-induced climate change are some of the key challenges facing humanity.

WMO supports climate policy-making by providing authoritative advice and information on climate change mitigation and adaptation. WMO draws from the best available scientific expertise from the National Hydrological and Meteorological Services of its Members, and international data centres and agencies. Moreover, WMO promotes a better understanding of the societal impacts of climate change within the United Nations system.

Regional Climate Outlook Forums (RCOFs) produce consensus-based, user-relevant climate outlook products in real time through regional cooperation and partnership in order to reduce climate-related risks and support sustainable development for the coming season in sectors of critical socioeconomic significance for the region in question.

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Developing countries, least developed countries (LDCs) and small island developing states (SIDS) are particularly vulnerable to impact of climate extremes, including drought which could lead to water crisis or severe food shortage.

The start of 2019 has been marked by high impact weather in many parts of the world, including record heat, wildfires and rainfall in South America and Australasia, dangerous and extreme cold in North America, and heavy snowfall in the Alps and Himalayas.

In a clear sign of continuing long-term climate change associated with record atmospheric concentrations of greenhouse gases, 2015, 2016, 2017 and 2018 have been confirmed as the four warmest years on record.